Fatal error: Uncaught Error: Class 'Symfony\Component\DependencyInjection\Dumper\Dumper' not found in /var/www/typo3/vendor/symfony/dependency-injection/Dumper/YamlDumper.php:37 Stack trace: #0 {main} thrown in /var/www/typo3/vendor/symfony/dependency-injection/Dumper/YamlDumper.php on line 37